CSHARP-1823: Minor change to how MaxStaleness is validated against HeartbeatInterval and IdleWritePeriod.

rstam · rstam · commit f9af52884473 · 2016-11-18T11:28:52.000-06:00
diff --git a/src/MongoDB.Driver.Core/Core/Clusters/ServerSelectors/ReadPreferenceServerSelector.cs b/src/MongoDB.Driver.Core/Core/Clusters/ServerSelectors/ReadPreferenceServerSelector.cs
@@ -255,20 +255,43 @@ private void EnsureMaxStalenessIsValid(ClusterDescription cluster)
         {
             if (_maxStaleness.HasValue)
             {
-                var primary = SelectPrimary(cluster.Servers).SingleOrDefault();
-                var primaryIdleWritePeriod = primary?.IdleWritePeriod;
+                TimeSpan heartbeatInterval;
+                TimeSpan idleWritePeriod;
 
-                foreach (var server in cluster.Servers)
+                var primary = SelectPrimary(cluster.Servers).SingleOrDefault();
+                if (primary != null)
+                {
+                    heartbeatInterval = primary.HeartbeatInterval;
+                    idleWritePeriod = primary.IdleWritePeriod;
+                }
+                else
                 {
-                    if (server.Type == ServerType.ReplicaSetPrimary || server.Type == ServerType.ReplicaSetSecondary)
+                    ServerDescription secondaryWithGreatestLastUpdateTime = null;
+                    foreach (var secondary in SelectSecondaries(cluster.Servers))
                     {
-                        var heartbeatInterval = server.HeartbeatInterval;
-                        var idleWriteTime = primaryIdleWritePeriod ?? server.IdleWritePeriod;
-                        if (_maxStaleness.Value < heartbeatInterval + idleWriteTime)
+                        if (secondaryWithGreatestLastUpdateTime == null || secondary.LastUpdateTimestamp > secondaryWithGreatestLastUpdateTime.LastUpdateTimestamp)
                         {
-                            throw new Exception("Max staleness must greater than or equal to heartbeat interval plus idle write period.");
+                            secondaryWithGreatestLastUpdateTime = secondary;
                         }
                     }
+
+                    if (secondaryWithGreatestLastUpdateTime == null)
+                    {
+                        return;
+                    }
+
+                    heartbeatInterval = secondaryWithGreatestLastUpdateTime.HeartbeatInterval;
+                    idleWritePeriod = secondaryWithGreatestLastUpdateTime.IdleWritePeriod;
+                }
+
+                if (_maxStaleness.Value < heartbeatInterval + idleWritePeriod)
+                {
+                    var message = string.Format(
+                        "Max staleness ({0} ms) must greater than or equal to heartbeat interval ({1} ms) plus idle write period ({2} ms).",
+                        (int)_maxStaleness.Value.TotalMilliseconds,
+                        (int)heartbeatInterval.TotalMilliseconds,
+                        (int)idleWritePeriod.TotalMilliseconds);
+                    throw new Exception(message);
                 }
             }
         }
diff --git a/tests/MongoDB.Driver.Core.Tests.Dotnet/Specifications/max-staleness/tests/ReplicaSetNoPrimary/IdleWritePeriod.json b/tests/MongoDB.Driver.Core.Tests.Dotnet/Specifications/max-staleness/tests/ReplicaSetNoPrimary/IdleWritePeriod.json
@@ -36,7 +36,7 @@
         {
             "address": "b:27017",
             "avg_rtt_ms": 50,
-            "idleWritePeriodMillis": 9000,
+            "idleWritePeriodMillis": 11000,
             "lastUpdateTime": 0,
             "lastWrite": {
                 "lastWriteDate": {
@@ -65,7 +65,7 @@
             {
                 "address": "b:27017",
                 "avg_rtt_ms": 50,
-                "idleWritePeriodMillis": 9000,
+                "idleWritePeriodMillis": 11000,
                 "lastUpdateTime": 0,
                 "lastWrite": {
                     "lastWriteDate": {
diff --git a/tests/MongoDB.Driver.Core.Tests/Specifications/max-staleness/tests/ReplicaSetNoPrimary/IdleWritePeriod.json b/tests/MongoDB.Driver.Core.Tests/Specifications/max-staleness/tests/ReplicaSetNoPrimary/IdleWritePeriod.json
@@ -36,7 +36,7 @@
         {
             "address": "b:27017",
             "avg_rtt_ms": 50,
-            "idleWritePeriodMillis": 9000,
+            "idleWritePeriodMillis": 11000,
             "lastUpdateTime": 0,
             "lastWrite": {
                 "lastWriteDate": {
@@ -65,7 +65,7 @@
             {
                 "address": "b:27017",
                 "avg_rtt_ms": 50,
-                "idleWritePeriodMillis": 9000,
+                "idleWritePeriodMillis": 11000,
                 "lastUpdateTime": 0,
                 "lastWrite": {
                     "lastWriteDate": {

Original file line number	Diff line number	Diff line change
`@@ -255,20 +255,43 @@ private void EnsureMaxStalenessIsValid(ClusterDescription cluster)`
`255`	`255`	`{`
`256`	`256`	`if (_maxStaleness.HasValue)`
`257`	`257`	`{`
`258`		`- var primary = SelectPrimary(cluster.Servers).SingleOrDefault();`
`259`		`- var primaryIdleWritePeriod = primary?.IdleWritePeriod;`
	`258`	`+ TimeSpan heartbeatInterval;`
	`259`	`+ TimeSpan idleWritePeriod;`
`260`	`260`
`261`		`- foreach (var server in cluster.Servers)`
	`261`	`+ var primary = SelectPrimary(cluster.Servers).SingleOrDefault();`
	`262`	`+ if (primary != null)`
	`263`	`+ {`
	`264`	`+ heartbeatInterval = primary.HeartbeatInterval;`
	`265`	`+ idleWritePeriod = primary.IdleWritePeriod;`
	`266`	`+ }`
	`267`	`+ else`
`262`	`268`	`{`
`263`		`- if (server.Type == ServerType.ReplicaSetPrimary \|\| server.Type == ServerType.ReplicaSetSecondary)`
	`269`	`+ ServerDescription secondaryWithGreatestLastUpdateTime = null;`
	`270`	`+ foreach (var secondary in SelectSecondaries(cluster.Servers))`
`264`	`271`	`{`
`265`		`- var heartbeatInterval = server.HeartbeatInterval;`
`266`		`- var idleWriteTime = primaryIdleWritePeriod ?? server.IdleWritePeriod;`
`267`		`- if (_maxStaleness.Value < heartbeatInterval + idleWriteTime)`
	`272`	`+ if (secondaryWithGreatestLastUpdateTime == null \|\| secondary.LastUpdateTimestamp > secondaryWithGreatestLastUpdateTime.LastUpdateTimestamp)`
`268`	`273`	`{`
`269`		`- throw new Exception("Max staleness must greater than or equal to heartbeat interval plus idle write period.");`
	`274`	`+ secondaryWithGreatestLastUpdateTime = secondary;`
`270`	`275`	`}`
`271`	`276`	`}`
	`277`	`+`
	`278`	`+ if (secondaryWithGreatestLastUpdateTime == null)`
	`279`	`+ {`
	`280`	`+ return;`
	`281`	`+ }`
	`282`	`+`
	`283`	`+ heartbeatInterval = secondaryWithGreatestLastUpdateTime.HeartbeatInterval;`
	`284`	`+ idleWritePeriod = secondaryWithGreatestLastUpdateTime.IdleWritePeriod;`
	`285`	`+ }`
	`286`	`+`
	`287`	`+ if (_maxStaleness.Value < heartbeatInterval + idleWritePeriod)`
	`288`	`+ {`
	`289`	`+ var message = string.Format(`
	`290`	`+ "Max staleness ({0} ms) must greater than or equal to heartbeat interval ({1} ms) plus idle write period ({2} ms).",`
	`291`	`+ (int)_maxStaleness.Value.TotalMilliseconds,`
	`292`	`+ (int)heartbeatInterval.TotalMilliseconds,`
	`293`	`+ (int)idleWritePeriod.TotalMilliseconds);`
	`294`	`+ throw new Exception(message);`
`272`	`295`	`}`
`273`	`296`	`}`
`274`	`297`	`}`